A military base in Iraq housing a pro-Iranian militia has been damaged in an explosion, killing one and wounding eight, security officials there have said.

Iraq's military reported no drones or fighter jets in the area before or during the blast.

But the militia organisation involved, the Popular Mobilisation Forces (PMF), blamed an attack.

It comes amid heightened tensions between Israel and Iran.

The PMF is an umbrella organisation that contains several pro-Iranian militias that are part of the network of proxies that Tehran has been able to use to advance its interests across the Middle East for years.

Those militias have attacked US personnel and interests in Iraq on a number of occasions in the past, with the aim of trying to force the remaining US troops to leave the country. The US has regularly struck back at the militias.

The Pentagon has, however, moved swiftly to deny any involvement in this incident.

It comes as the long-running confrontation between Israel and Iran has recently moved into a new, more perilous phase, amid tensions heightened by the war in Gaza.

In contrast to the shadow war they have been engaged in for many years, both countries appear to have directly attacked each other's territory.

There was a presumed Israeli strike carried out near the Iranian city of Isfahan early on Friday morning.

The attack was an apparent response to a major drone and missile barrage that Tehran launched on Israel six days earlier.

The Iranian action was in retaliation for an earlier strike on senior Iranian military commanders in the Syrian capital Damascus - widely believed to have been carried out by Israel.

While the conflict still seems contained to some extent for now, the Iranian foreign minister has warned that Iran will deliver an immediate and "maximum" response if Israel launches significant attacks on its interests.

The explosion at Kalso military base, about 50km (30 miles) south of Baghdad, happened early on Saturday morning, the military said.

A member of the PMF was killed in the blast and eight others were wounded.

In a statement, the PMF said its chief of staff Abdul Aziz al-Mohammedawi had visited the base to review what investigators had found so far.

The Iraqi military also said it was investigating the cause of the explosion and fire at the base.

"The air defence command report confirmed, through technical efforts and radar detection, that there was no drone or fighter jets in the air space of Babil before and during the explosion," a statement read.

The US military's Central Command denied what it said were reports the US had carried out air strikes in Iraq in a post on X, formerly known as Twitter.